I believe mirc is delphi code, not that it would be much harder to do.
- Make .mrc files open in mIRC when double clicked. If already loaded, open script editor and select script, otherwise load it and do the same.
As long as this feature is made completely optional (changable from WITHIN each mirc installation), something like 'allow loading of script through explorer' or similar, then im all for it. Otherwise is should skip the 'load it and do the same' part for that mirc instance. Not sure how easy it would be to implement though, since file associations are made to specific installations (maybe it could use a call to dde method or something i dont know).
I guess just changing the file association would be easiest but many users are not aware of how to do that.